Russia and the United States are set to resume talks aimed at avoiding accidents in Syrian air space as the two countries conduct separate bombing campaigns.

U.S. Defense Department press secretary Peter Cook said Friday that a second round of talks could take place within the next few days.

The United States, which opposes Moscow's support for Syrian President Bashar al-Assad, has ruled out cooperation with Russia, but has agreed to work on air safety procedures.

Russian planes crossed into Turkish airspace several days ago, triggering an immediate protest from Turkey and a vow from NATO that it will defend its member nation. A Russian aircraft also came within a few kilometers of an American drone.

This past week, Moscow fired cruise missiles into Syria from ships in the Caspian Sea, and the U.S. says four of them went awry and crashed in Iran. Moscow denies any of its missiles went awry.

Talks are likely to deal with how much separation there should be between U.S. and Russian aircraft and which language crews should use for communications.

The news of the talks came as the U.S. announced earlier Friday a change in a $500 million Pentagon-led program to train and equip Syrian rebels fighting Islamic State militants.

The operation will shift away from vetting moderate Syrian rebels and training them in Jordan, Saudi Arabia, Qatar and the United Arab Emirates.

"We are going to pause that for now," Under Secretary of Defense for Policy Christine Wormuth told reporters Friday on a White House conference call, "but there may be an opportunity in the future where the situation on the ground is more fruitful."

Instead, the program will provide air support and basic equipment and training to vetted opposition group leaders, White House officials said.

"We're going to be vetting leaders as opposed to each individual fighter," Wormuth said.

The Pentagon will use a small training center in Turkey to teach these leaders skills, including how to call in airstrikes. It will also better equip trusted units on the ground fighting against the Islamic State.

"Is it best to take those guys out and put them through training programs for many weeks, or to keep them on the line fighting and to give them additional enablers and support?" said Brett McGurk, the White House deputy envoy to the Global Coalition to Counter Islamic State. "I think the latter is the right answer, and that's what we're going to be doing."

Early efforts unsucessful

The Pentagon-led train-and-equip program had trained only a few dozen fighters, much fewer than the original goal of thousands.

"The way the program was proceeding was extremely ill-conceived, and it didn't match the reality of Syrian battlefields," Jeffrey White of the Washington Institute for Near East Policy told VOA. "It had virtually no chance of success the way they were going about it."

Officials have acknowledged significant challenges. Deputy national security adviser Ben Rhodes said the administration had been willing to make "corrections" when it saw things "not working."

"I wasn't happy with the early efforts of the program," Defense Secretary Ash Carter said Friday in London. "So we have devised a number of different approaches."

Carter said the work the United States has done with Kurdish forces in northern Syria has proved effective, calling it "exactly the kind of example" that should be pursued with other groups in Syria going forward.

"I remain convinced that a lasting defeat of ISIL in Syria will depend in part on the success of local, motivated and capable ground forces," Carter said in a statement issued by the Pentagon, using an acronym for Islamic State.

"I believe the changes we are instituting today will, over time, increase the combat power of counter-ISIL forces in Syria and ultimately help our campaign achieve a lasting defeat of ISIL," he said.

U.S. Senator John McCain, a frequent critic of the Obama administration's approach to the conflict in Syria, said the Pentagon's revised train and equip program involving Syrian rebels suffers the same primary flaw that harmed the program from the start.

"As President Obama conceded last week, the administration's insistence that U.S.-trained Syrian forces only fight [Islamic State militants] — even as the Assad regime has slaughtered over 200,000 Syrians — has made it impossible to generate a viable indigenous ground force in Syria that can produce significant effects on the battlefield," McCain said in a statement. "It is inexplicable that the administration acknowledges this problem yet refuses to fix it."